Elastic honing material

ABSTRACT

An abrasive elastic material composed of an abrasive fixedly bonded to an elastic substrate and the process for producing this material and conforming it into the various shapes needed for its use with power tools and the like. The material can be used on any of a wide variety of mechanical abrading devices, and has the advantages of conforming to irregular surfaces, resisting ripping and tearing, reducing vibration, allowing more subtlety in the application of pressure with the abrading surface and prolonged useful life. It differs from the material making up traditional abrading elements, such as honing belts, in its elasticity

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to the field of abrading, sanding, buffing, polishing, deburring, honing and other procedures used in the preparation of material surfaces. More particularly the present invention relates to the field of abrasive surfaces used on power tools to carry out such procedures and to the means for producing and using such surfaces. More particularly yet, the present invention relates to such surfaces, to specific applications of such surfaces, and to the means for producing such surfaces where such surfaces display a significant elasticity and resilience not found in abrasive surfaces produced and used heretofore.

[0003] 2. Description of Prior Art

[0004] Abrading, sanding, buffing, polishing, deburring, and honing (hereinafter “honing”) of material surfaces has been an integral part of carpentry and metalwork for centuries. For at least 100 years, these procedures have been carried out with the benefit of power tools used to rapidly draw abrasive objects across the surface to be honed. These abrasive objects include but are not limited to a moving belt, a disc, drum or other attachment that is covered with an abrasive material for the purpose of abrading irregular surfaces.

[0005] In spite of this long history, there continue to be certain types of irregular surfaces that present significant problems to the persons and equipment seeking to hone them, problems inherent in the nature of the abrasive object sought to be used in the honing procedure. Such abrasive objects are most often composed of a paper or fabric substrate to which the abrasive compound is bonded or otherwise adhered, or, alternately, the abrasive material is a fabric that is inherently abrasive. These objects are generally flexible, though not resilient or elastic; it is in the lack of resilience/elasticity that the problem lies, the applications where it shows up being the honing of corners, edges, highly irregular surfaces and the interior of small or irregularly-shaped enclosures. These traditional abrasive materials rip, tear, and by other means reach a premature end when used to hone sharp or, in other ways irregular, surfaces. This difficulty is aggravated by the means by which the abrasive object is affixed to the abrading implement. The abrading object is typically mounted on a rigid plane, disc, wheel, drum, bore or other attachment which provides no means by which the abrading surface can bend to conform to irregularities in the surfaces to be honed. This rigid mounting surface also induces vibration in the device when applied to the surface to be abraded, thereby hindering the user's control of the device.

[0006] Present methods intended to address the aforementioned problems include an inflatable cylindrical abrading attachment consisting of a cylindrical rubber casing containing an inflatable elastic bladder, an abrading sleeve to be slipped over the outside of the bladder. The sleeve features longitudinal slots that allow the bladder to expand within it. Although this approach provides a flexible, resilient backing for the abrading surface, the abrading surface itself still resides on a sleeve of paper or fabric substrate that is not elastic. This means that the abrading material still is prone to ripping and tearing when used on irregular or jagged surfaces.

[0007] Another approach to solving the problem of the premature destruction of the abrading surface is disclosed by Klein (U.S. Pat. No. 5,792,544); it involves using a backing surface that is more flexible than paper and the fabrics traditionally used and is directed to an improved technique for the binding of abrasive material to the substrate. While this invention is intended to prolong the useful life of the grinding surface, the flexible substrate—described as being composed of cotton or poly/cotton fabric—continues to be non-elastic and thus still prey to the problems described above.

[0008] An abrading device that does provide an elastic backing for the abrasive material is that disclosed by Pangburn (U.S. Pat. Nos. 4,572,222 and 4,459,987); it consists of a layer of flexible, stretchable silicone polymer with an embedded layer of abrasive pumice particles. The device of Pangburn is specifically for personal cosmetic uses, particularly the etching of fingernails, rather than industrial use; it is incompatible with industrial abrading needs because the silicone polymer substrate is not sufficiently durable to withstand the abrasion of most industrial applications. Furthermore, the nature of the bond between the substrate and the abrasive grit in this invention is apparently such that it would not hold fast in industrial uses, in part because the significant stretching of the silicone polymer substrate would tend to weaken the substrate-abrasive bond.

[0009] Therefore, what is needed is an abrasive material adapted to the use of modern power tools that is sufficient elastic to comply with irregular surfaces and to dampen the vibration typically caused by such tools. What is further needed is such abrasive material provided in the large variety of shapes required by modern honing demands.

SUMMARY OF THE INVENTION

[0010] The device of the present invention is abrasive material using a backing that is at once elastic and also durable enough to overcome the ripping and snagging problems caused by traditional abrasive material used for honing. More particularly, the device of the present invention consists of strips of abrasive material—such as sandpaper, nonwoven abrasive fabric, or non-backed abrasive compounds—bonded to a substrate composed of natural rubber, synthetic rubber, or other suitable elastic materials. The abrasive may be affixed to the substrate in a variety of patterns to suit different needs; for example, overlapping strips, side-abutted strips, strips in a spiral pattern, intermittently spaced strips. The abrasive material is bonded to the elastic substrate through a process involving application of chemical solvents and adhesives, as well as heat and pressure. The resulting material can be cut into a variety of shapes to fit belts, discs, drums, drill chucks, hones, and other abrading devices.

[0011] Thus the process described in the present invention produces an abrasive material with the characteristics of pliability and elasticity. In belt form, this material can easily be affixed to and removed from a belt sanding device without the use of any release mechanisms such as are needed for non-elastic abrasive belts. In the form of sleeves and cuffs of varying lengths and diameters, this device of the present invention can be easily and interchangeably fitted onto any of a number of sanders, grinders, polishers, buffers, bores and drills, thereby increasing the versatility of these devices. The elasticity of the device of the present invention allows it to conform to irregular objects and work easily around edges and corners, while resisting tearing and ripping from being run over jagged surfaces. This device provides the added advantage of reducing vibration and allowing the user to apply more graduated force to the surface being abraded, thereby avoiding the scuffs and mars that often result from using such a device in conjunction with conventional abrading materials. Because of its advantages, the device of the present invention is applicable both to professional honing jobs and to those carried out by the homeowner. For the latter application, the device of the present invention will be configured so as to fit onto the standard power drill found around the house.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 shows both the uncut rubber substrate in roll form and the cut piece of rubber substrate as wrapped on a mandrel as part of the fabrication process used in the Preferred Embodiment of the present invention.

[0013]FIG. 1a shows the rubber substrate on the mandrel with the abutting edges of the substrate being crimped so as to effect a tight seam along that line of joinder as part of the Preferred Embodiment process of the present invention

[0014]FIG. 2 is a view of the abrasive strips as they are applied to the mandrel-mounted rubber substrate in the Preferred Embodiment Process.

[0015]FIG. 3 shows the mandrel/rubber-substrate/abrasive assembly being wrapped prior to treatment in the oven as part of the Preferred Embodiment process.

[0016]FIG. 4 depicts the sleeve of treated, completed abrasive material in the midst of being removed from the mandrel as a further step in the Preferred Embodiment process.

[0017]FIG. 5 is a completed sleeve of elastic abrasive material with a section cut away from the sleeve in order to form an elastic honing belt, the device of the Preferred Embodiment of the present invention.

PREFERRED EMBODIMENT OF THE INVENTION

[0018] The Figures depict in step-by-step fashion the Preferred Embodiment process of the present invention for producing elastic honing material. This Preferred Process is as follows. As shown in FIG. 1, an elastic substrate section 1 is cut from a stock roll 100 of natural rubber one-sixteenth of an inch in thickness, the section 1 selected to have a length substantially equal to the circumference of a mandrel 2 onto which the section 1 is to be wrapped. Prior to wrapping the section 1 onto the mandrel 2, a layer of solvent is applied to the edges of the section of rubber that will abut one another after the wrapping is effected. Because every type of rubber requires a different solvent, the chemical agent used will vary depending on the composition of the substrate. For natural rubber, the substrate of choice in the Preferred Embodiment of the present invention, xylol or xylene is typically used as the solvent. After the solvent has been applied, the section 1 is wrapped onto the mandrel 2, which itself has been previously treated with a release agent. As shown in FIG. 1a, the side edges of the section 1 are abutted together and joined in a seam 3 by means of a stitching tool 20. A layer of tactifying agent is then applied over the exposed surface of the substrate. CHEMLOC-AR27 being the choice of tactifying agent in the Preferred Embodiment of the present invention.

[0019] With the tactifying agent in place, a layer of abrasive material 5 is prepared to be applied to the tactified surface of the section 1 wrapped on the mandrel 2, as depicted in FIG. 2. In the Preferred Embodiment, the abrasive material 5 is sandpaper, 100-grit and x-weight or j-weight as supplied by either 3M or KLINGSPORE. The weight of the abrasive can vary over the entire range of availability of such sandpaper. However, most commonly in the Preferred Embodiment it will be x-weight or j-weight. In order to prepare the abrasive material 5 for application to the tactified surface of section 1, the sheet of sandpaper is cut to have a length equal to the length of the rubber substrate sheet and spread out, abrasive side down. The paper backing of the sheet is washed by means of a brush and acetone. Once the acetone has evaporated, a layer of bonding agent is applied to the paper side of the sheet, the bonding agent being CHEMLOC 250 or 250X in the Preferred Embodiment. With this preparation, the sandpaper sheet is run through a slicing device (not shown) so as to cut the sandpaper sheet into narrow strips 4. The width of the abrasive strips 4 is one-quarter of an inch in the Preferred Embodiment; however, different widths will be required for different end applications. After the bonding agent has dried, the strips 4 are applied longitudinally along the exposed face of the section 1 deployed on the mandrel 2 with the abrasive face outward, all as illustrated in FIG. 2. In order to work toward an end product that is a honing belt, the Preferred Embodiment device of the present invention, the abrasive strips 4 are applied in an overlapping pattern so that a part of each of the abrasive strips 4 overlaps approximately one-half of the adjacent strip. Such overlap introduced at this stage results in a honing belt that does not display any gaps in its abrasive surface when stretched. For other applications, abrasive strips of varying widths can be applied to the substrate in side-abutting, spaced, or spiral patterns.

[0020] Next, the entire assembly, while still on the mandrel 2, is wrapped tightly with a layer of three-inch wide MYLAR sheeting 6, and then with a layer of three-inch wide nylon sheeting 7, as shown in FIG. 3. The mandrel 2 wrapped with the section 1, the abrasive strips 4, the MYLAR sheeting 6 and the nylon sheeting 7 is then placed in an oven where it is exposed to elevated temperature and pressure and “baked” for a period of time. The temperature, pressure, and baking time will vary depending on the type of material used for the section 1; for the Preferred Embodiment material, a temperature of 285° F., a pressure of 65-70 psi, and a baking time of 1.5 hours are used. Following this baking, the mandrel 2 is removed from the oven and the MYLAR sheeting 6 and nylon sheeting 7 are both cut away, leaving behind a finished roll 10. Then, as shown in FIG. 4, turnakel devices 8 are affixed to the finished roll 10, one to each end of the mandrel 2, and tightened. This step creates a substantially sealed pocket between the inner surface of the finished roll 10 and the outer surface of the mandrel 2. Next a compressed-air-hose nozzle 9 is forced under one of the turnakels devices 8 and thus into the pocket between the finished material 10 and the mandrel 2. When air is applied through the nozzle 9, thereby loosening the finished material 10 from the mandrel 2. The finished material 10 is then slid off the mandrel 2 as a sleeve. This sleeve of finished material 10 is then sliced into individual honing belts 11, all as shown in FIG. 5. The widths of the individual honing belts 11 are chosen to fit the end application, or, alternatively, can have a variety of magnitudes

[0021] An alternate embodiment of the present invention would ultilize chemical adhesives rather than chemical bonding agents in fixing the abrasive material to the elastic subtrate. While this technique will result in a bond that is not as strong and durable as the aforementioned Preferred Embodiment, it has the advantage of greater cost-effectiveness in certain applications. Specifically, in applications where a large section of elastic abrasive comprised of a thick layer of rubber substrate is needed, the ability to remove the abrasive material from the rubber backing once the abrasive has been expended through use would be advantageous in comparison with having to replace the entire elastic honing belt. The reason for this advatage is that rubber substrate that exceeds a particular thickness can be quite costly. While the costly rubber substrate itself is not affected through repeated use, the abrasive material that is expended is relatively inexpensive. The adhesive-fixing method would permit the expended abrasive material to be stripped from the substrate and new abrasive to be applied, thus saving the cost of replacing the rubber substrate along with the expended abrasive material.

[0022] As yet another alternative embodiment, a process producing a honing belt without the paper backing for the abrasive compound can be used. This process differs from that of the Preferred Embodiment of the present invention only in that the sandpaper will be treated with bonding agent on its abrasive side, after which the sandpaper will be applied to the elastic section in a single sheet, rather than in strips, and it will be applied with the abrasive side down. After that everything proceeds as before until the mandrel is removed from the oven. At that point, the exposed paper backing of the sandpaper is peeled away, leaving only the abrasive particles bonded to the substrate. Other abrasives can be used in place of the sandpaper, including, but not limited to, non-woven abrasive fabric such as 3M SCOTCHBRITE, felt, emery cloth or leather. These abrasive materials would be applied to the substrate in strips, just as described in the application of the sandpaper. 

We claim:
 1. An elastic abrasive material for use in honing operations, said material comprising an abrasive surface affixed to an elastic substrate.
 2. Elastic abrasive material as claimed in claim 1 wherein said abrasive surface is comprised of sand particles similar in size and distribution to that found in standard sandpaper.
 3. A honing belt created from the elastic abrasive material claimed in claim 2 wherein said belt comprises a continuous loop of said material, said loop having a diameter substantially equal to a diameter of a powered honing device.
 4. A honing disc created from the elastic abrasive material claimed in claim 3 wherein said disk has a diameter substantially equal to a diameter of a powered grinding wheel with which said disk is intended to be used.
 5. A honing belt as described in claim 3 , wherein said powered honing device is a standard home drill and said honing belt is sized so as to fit over a chuck of said drill.
 6. A method for producing elastic abrasive material suitable for cutting into various sizes and shapes to be used with a variety of power tools for the purpose of honing surfaces, said method comprising the steps of selecting a sheet of sandpaper having an abrasive side and a paper side, affixing said sandpaper to an elastic backing section such that said abrasive side is exposed and said paper side is adjacent to said elastic backing, treating said elastic backing section bearing said sandpaper so as to effect an improved bonding between said sandpaper and said elastic backing section, cutting said elastic backing section bearing said sandpaper into shapes suitable for use with said variety of power tools.
 7. The method for producing elastic abrasive material as described in claim 6 wherein said step of treating comprises exposing said section bearing said sandpaper to increased temperature and elevated pressure for a period of time.
 8. The method of claim 7 wherein said period of time is substantially equal to 1.5 hours and said elevated pressure is substantially equal to 65-70 psig.
 9. The method of claim 8 wherein said increased temperature is substantially equal to 285° F.
 10. The method of claim 9 wherein said elastic backing section is rectangular in shape having a width and a length and wherein the method comprises the additional step of wrapping said elastic backing section on a mandrel of circumference substantially equal to said length and of breadth substantially equal to said width prior to said affixing of said sandpaper to said elastic backing section, and wherein said wrapping results in said mandrel being substantially covered by said elastic backing section with a first edge of said elastic backing section abutting a second edge of said elastic backing section at a line of joinder on said mandrel.
 11. The method of claim 10 comprising the additional step of cutting said sandpaper into a plurality of strips, each of said strips being substantially equal in length to said breadth, prior to said affixing of said sandpaper to said elastic backing section.
 12. The method of claim 11 comprising the additional step of wrapping said sandpaper with a MYLAR sheeting and a nylon sheeting prior to said step of treating, wherein said MYLAR sheeting and said nylon sheeting are then removed following said step of treating.
 13. The method of claim 12 comprising the additional step of pressurizing an interface between said elastic backing section and said mandrel following said step of treating, so as to break any adhesion existing between said elastic backing section and said mandrel following said step of treating.
 14. The method of claim 13 comprising the additional step of slipping said elastic back section off of said mandrel following said pressurization.
 15. The method of claim 14 wherein following said step of slipping said elastic back section off of said mandrel, said elastic backing section, now adhering to said sandpaper, is sliced so as to form a plurality of honing belts with inner circumferences substantially equal to said circumference of said mandrel.
 16. The method of claim 15 wherein said affixing of said strips to said elastic backing section is done in such manner that each of said strips overlaps a first adjacent strip and is overlapped by a second adjacent strip.
 17. The method of claim 15 wherein said step of affixing said sandpaper to said elastic backing is carried out so that said paper side is exposed and said abrasive side is adjacent to said elastic backing section.
 18. The method of claim 16 wherein following said step of treating, said paper side is peeled away, leaving sand adhering to said elastic backing section.
 19. The method of claim 18 where said sandpaper has weight-x.
 20. A method for producing an elastic honing belt for use with power tools, said method comprising the steps of (a) Selecting a mandrel having a mandrel breadth and a mandrel circumference; (b) Selecting an extended sheet of elastic material having an elastic length equal to said mandrel circumference and an elastic width equal to said mandrel breadth; (c) Applying a release agent to a surface of said mandrel; (d) Wrapping said elastic material around said mandrel and joining ends of said elastic material together in a seam by means of a chemical bonding agent and stitching tool; (e) Selecting a sheet of abrasive material with an abrasive width substantially equal to said elastic width and an abrasive length substantially equal to said elastic length, wherein said sheet of abrasive material has a paper backing side and an abrasive side; (f) Cleaning said paper backing side; (g) Applying a chemical bonding agent to said paper backing side; (h) Cutting said sheet of abrasive material into a plurality of strips of uniform width; (I) Applying a layer of chemical tactifying agent to said elastic material wrapped on said mandrel; (j) Applying said strips longitudinally along said elastic material wrapped on said mandrel; (k) Tightly wrapping said abrasive material with MYLAR sheeting and with nylon sheeting; (l) Placing said mandrel containing said strips into an enclosure, wherein said enclosure is then pressurized and heated to an elevated temperature for a predetermined time interval, after which said interval, said mandrel is removed from said enclosure; (m) Removing said MYLAR and nylon from said strips; (n) Loosening treated elastic material from said mandrel by injecting compressed air between said elastic material and said mandrel; (o) Removing treated said elastic material from said mandrel as a sleeve and cutting said sleeve into honing belts of desired width. 